1. Field of the Invention
The present invention relates to diathermic instruments and, more particularly, to a disposable electrosurgical switch handle and a removable electrode blade that is capable of supplying a high frequency current to a patient.
2. Description of the Prior Art
Various forms of diathermic surgical tools have been suggested and utilized in the medical field for a considerable period of time. These instruments have been utilized, for example, to burn or cut tissue. Recently, these instruments have been improved to permit incisions and hemostasis with a minimum disturbance of adjacent tissue. These instruments have utilized radio frequency electrical energy generally in the range of half million cycles per second to over two million cycles per second. Generally, these instruments have utilized three different signals which are characteristically referred to as cutting signals, coagulation or hemostasis signals and a blend of signals or fulgurating signals which combine both the cutting and coagulation signals. These high frequency or radio frequency signals are generally applied to a patient by an electrode and conducted through the patient's body via a ground path provided by an electrode plate or indifferent plate that is maintained in contact with the patient's body. The application of the signals to the patient is through an electrosurgical electrode which applies the high frequency energy to a concisely concentrated point on the patient's body. The relatively large ground electrode plate provides an area for removing the applied energy without affecting the patient.
As is known, the actual cutting is accomplished by the concentrated application of high frequency electrical energy which effectively destroys the body cells directly beneath the electrosurgical electrode. The hemostasis or coagulation energy signals produce coagulation by the dehydrating or shrinking of the blood vessel walls around a contained clot of coagulated blood. This fusion or uniform coagulation of the blood vessel and its contents effectively seals off the flow of blood. Typically, such coagulation signals or pulses of energy have a dampened sinusoidal wave form.
The fulguration or blended signals, formed by combining the cutting and hemostasis signals, can be effectively utilized for accomplishing cutting and coagulation at the same time. Alternating periods of each signal are sometimes utilized to form the blended signals.
The choice of the particular mode of operation of the electrosurgical instrument must frequently be accomplished with a minimum of diversion of the doctor from the site of surgery. In addition, the doctor must be able to maintain his hands on the switching handle that contains the electrosurgical electrode. Finally, it is particularly desirable that the electrosurgical instrument be economically produced, so that it can be disposed after use, thus, insuring a new sterile instrument for each operation.
The Judson U.S. Pat. No. 3,885,569 is cited to disclose an electrosurgical unit for generating electrical signals for an electrosurgical electrode.
The Friedman U.S. Pat. No. 3,875,945 discloses an electrosurgical switching handle that is capable of being operated without a ground plate and utilizes a spring biased wire member for holding the surgical electrode blade. A pressure sensitive two position control switch is located in an area adjacent the patient and may either be foot operated or mounted on the handle approximate to the cutting tip. The doctor, by increasing the pressure of the control switch, is purportedly able to vary the level of output voltage from the power supply.
One commercial switch for an electrosurgical handle contains a centrally pivotable actuator that is capable of overcoming a biased spring contact on either side of the actuator.
The Burger U.S. Pat. No. 2,993,655 discloses a foot operated treadle switch for controlling the mode of operation between cut and coagulate position.
The Anderson U.S. Pat. Nos. 3,683,923 and 3,699,967, Judson U.S. Pat. No. 3,885,565, Gonser U.S. Pat. Nos. 3,804,096; 3,870,047; Jarrard U.S. Pat. No. 3,911,241; and Comerford, et al. U.S. Pat. No. 3,879,592 are cited of general interest.
It is the intention of the subject invention to provide a highly dependable and disposable electrosurgical switching handle that is compatible with the solid state technology that is providing a greater amount of electrical power for electrical surgical purposes.